1. Field of the Invention
The present invention relates to a hand tool, and more particularly to a multi-size wrench which is capable of driving different types of fasteners.
2. Description of the Prior Art
With the coming of automation, most of the works or assembling operations can be done automatically by machines. However, there are still some small assembly procedures that need to be done by hand tools, and also because they are easy to use, that's why the hand tools are developed constantly and becoming more and more perfect and practical. Let's take wrench as an example, although the jaw of an adjustable wrench is adjustable to fit different fasteners, the adjustable wrench is not so light and small that a user can carry it conveniently. Hence, a small and light conventional (nonadjustable) wrench is very useful in many circumstances; however, the operating size of such a wrench is fixed and unchangeable. Hence, Taiwan Pt 349458 discloses a hand tool 10, as shown in FIG. 1, which is defined in its work head 11 with a big engaging groove 111 and a small engaging groove 112 which correspond to the nominal fastener sizes in English and Metric units. As shown in FIG. 2, a 10-mm fastener A in Metric units is engaged in the big engaging groove 111, and as shown in FIG. 3, a ⅜-inch fastener B in English units is engaged in the small engaging groove 112, and thus the work head 11 of the hand tool 10 is adapted to fasteners in both metric and English units. However, Metric and English systems are not the only two systems appeared on the market, so the hand tool 10 won't be useful when it comes to the fasteners in other systems.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.